Gravitational collapse of a charged fluid sphere

Abstract

A class of solutions of Einstein's gravitational field equations is discussed which describes the collapse or expansion of a charged, perfect-fluid spherical distribution of matter. These solutions reduce in the appropriate limits to certain charged Newtonian polytropes. A physical interpretation of the collapsing configurations is given, and it is shown that these solutions can describe the gravitational collapse of a bounded, charged fluid around a charged black hole. In all these configurations the singular region is either a spacelike or a null hypersurface. Therefore, the final state of collapse cannot be described by the complete analytic extension of the Reissner-Nordstr\om spacetime. The special case of uniform density models is investigated in detail and it is shown that they describe the accretion of neutral matter by a charged black hole. On the basis of this analysis, it is suggested that for the realistic collapse of charged matter the singular region formed within the matter is either spacelike or null.